Headless Download Tests

Run the full Rust suite:

cd src-tauri
cargo test --all-targets

Run the queue-manager harness when changing aria2 scheduling, concurrency, and retry behavior:

cd src-tauri
cargo test --test queue_manager -- --nocapture

Run the media metadata smoke test with an explicit URL when changing yt-dlp integration:

cd src-tauri
FIRELINK_LIVE_YOUTUBE_URL='https://www.youtube.com/watch?v=dQw4w9WgXcQ' \
  cargo test filters_live_youtube_metadata_from_env --lib -- --ignored --nocapture